Barring mechanism for buttonhole sewing machines



July is, 1950 A. R. WOOD 2,515,753

BARRING MECHANISM FOR BUTTONHOLE SEWING MACHINES Filed June 22, 1948 6Sheets-Sheet 1 IN V EN TOR.

ykfllfiecl ll/00d v WITNESS ATTORNEY July I8, 1950 A. R. WOOD 2,515,753

BARRING MECHANISM FOR BUTTONHOLE SEWING MACHINES Filed June 22, 1948 6Sheets-Sheet 2 IN V EN TOR.

flzfied j 700001 BY WITNESS? ATTORNEY July 18, 1950 M A. R. OOD2,515,753

EARRING MECHANISM FOR BUTTONHOLE SEWING MACHINES Filed June 22, 1948 6Sheets-Sheet 3 INVENTOR.

Byu l/i'ed Wood a? WITNESS:

ATTORNEY July 18, 1950 A. R. WOOD BARRING MECHANISM FOR BUTTONHOLESEWING MACHINES Filed June 22, 1948 6 Sheets-Sheet 4 a INVENTOR. vqfleolll/0005 ATTORNEY July 18, 1950 A. R. WOOD 2,515,753

EARRING MECHANISM FOR BUTTONHOLE SEWING MACHINES- Filed June 22, 1948 sSheets-Sheet s zwsurox.

lflzfiwz Q. "1110001 WITNESS ATIDRNEY July 18, 1950 A. R. WOOD BARRINGMECHANISM FOR BUTTONHOLE SEWING MACHINES Filed June 22, 1948 6Sheets-Sheet 6 INVENTOR. L/I Zfi'ed W000i ATTORNEY Patented July 18,1950 UNITED STATES PATENT OFFICE EARRING MECHANISM FOR BUTTONHOLE SEWINGMACHINES Alfred R. Wood, Bridgeport, Conn, assignorto The SingerManufacturing Company, Elizabeth, N. J., a corporation .of New JerseyApplication June 22, 1948, Serial No. 34,374

4 Claims.

1 This invention relates to Sewing machines and more particularly tosewing machines of the buttonhole type having mechanism whereby thelength of the stitches is automatically increased at the end or ends ofthe buttonhole upon cessation of the feeding movements of the work-clampfor the purpose of producin barrin stitches.

The present invention is an improvement over the barring mechanismdisclosed in my prior Patent No. 2,411,493, issued Nov. 19,1946, and ithas for its primary object to provide a barring mechanism in which thecomponents thereof remain mutually operatively connected throughout theentire cycle of operation.

In the mechanism disclosed in my prior patent there is a completeseparation of certain of the members in the mechanism during the timethe said members are being shifted to effect a change in the amplitudeof vibration of the needle. The separation of the parts renders themechanism susceptible of faulty operation particularly during thereconnecting of the parts. This results from the fact that the parts ormembers to be mutually connected may not be in proper reg-' isterrelative to each other and, obviously, when this occurs theinstantaneous recoupling of the members is impossible. The fact that themembers of the present barring mechanism are notseparated at any timeduring themachine'cycle renders the same more positive in its action,without any chance of defective operation incident to the interruptionof the operative rela: tionship of the parts comprising the mechanism.With my improved barring mechanism, change in the amplitude of vibrationof the needle is instantaneous and positive, regardless of whenthemechanism is actuated in the stitching cycle.

Further advantages and beneficial results in operation will be apparentfrom the following description of an illustrative embodiment of myinvention taken in connection with the accompanying drawings, in which:i

Fig. 1 is a right side elevational view of a portion of a buttonholesewing machine embodying the present invention, the head of the .machinebeing sectioned to disclose the needle-bar vibratory frame.

Fig. 2 is a top planview of the bracket-ar of the sewing machine.

Fig. 3 is an enlarged top plan view of the needle-bar vibratingmechanism and the barstitch counting device, showing the relativepositions of the component parts thereof when'the machine is producingthe side stitches oi'the buttonhole.

Fig. 4 is a view similar to Fig. 3, but with the bar-stitch countingmechanism removed to show more distinctly the details of the needle-barvibrating mechanism.

Fig. 5 is a view similar to Fig. 3, with the components of theneedle-bar vibrating mechanism intheir relative positions at the end ofthe sidestitching operation and just before the parts are shifted intotheir barring position.

Fig. 6 represents an enlarged vertical sectional view takensubstantially along the line 66, Fig.

2, but with the parts located in the position" shown in Fig. 5.

Fig. 7, is a top plan view similar to Fig. 3, but

with the needle-bar vibrating mechanism in pa; sition to produce therelatively long barringstitches and. the bar-stitchcounting device opf;crating to determine the number of stitches coinprising the bar. I I

Fig. 8 represents an enlargedvertical sectional view taken substantiallyalong the line 8- 8',

Fig. 2.

Fig. 9 is a view similar to Fig. 7, but with the bar-stitch countingdevice advanced to a posi-;' tion in which it is about to releasetheneedle-f bar vibrating mechanism from its barring p0 sition, so thatsaid vibrating mechanism can be spring-returned to its side-stitchingposition.

Fig. 10 represents an enlarged horizontal sec tional view takensubstantially along the use l0-!0, Fig. 1, showing in elevation the camforeffecting an interruption in the feed of the workclamp andforshifting the needle-bar vibrating mechanism for S de-stitching tobar-stitchin' position. v Fig. 11' represents a horizontal sectionalview-f taken substantially along the line ll-I I, Fig. 1.: Fig. 12'represents an enlarged sectional V ew" taken substantially along theline l2-l2, Fig. 5.

Fig. 13 represents a sectional View taken sub 7 stantially along theline [3-43, Fig. 3.

Fig. 14 represents a sectional view taken sub;

stantially along the line '|4 |4; Fig. '1.

by spur-gears l5, (5, H and 18, Fig. 2, to a countershaft l9 driven by abelt adapted to run upon a nest of pulleys 25 carried by thecountershaft :9. For a detailed description of the mainshaft drive,reference may be made to my U. S. Patent No. 2,338,611, issued Jan. 4,1944.

The stitch-forming mechanism of the machine includes an eye-pointedthreadsca-rrying needle 2!, Fig. 1, carried. in the lower end of aneedle-- bar 22 journaled for endwise reciprocatory move? ments inspaced bearings formed in a vibratory needle-bar-gate 23 supported uponpintles 24 within the head 3. The needle-bar 22 may derive itsreciprocatory movements from the mainr shaft M by means of any usual orsuitable connections therewith. Cooperating with the needle in theformation of stitches is any suitable form of lolo' p-taker (not shown)located beneath the bed The work to be buttonholed is adapted to be heldin a work-clamp, Fig. 1, comprising the sual lower workrplate 25 and theupper clampfoot 25, {The work-clamp is slowly moved in step-by-stepfashion under the endwise reciproatery and la erall vibratory needle 2!,first away from the machine-frame standard (to the left Fig. 1) and thentowards the standard to ause the and seco d rows of side zigz stitchesto be laid side by side in the work. The Werk el mp d riv s i s step-bystep mov m n rom t usua --feed-e r not sh wn) carried n the we e ot avertical ed-S af 27 journaled in the machine-frame. The OOImectiehbetween the work clamp and the fe m and the manner n wh h he f -caminterm t en y ro ate s f ly illust a ed a sc bed in my bo e m t n dprior Pa en o, .4111 93. nclud d n th mechanism f r intermittentlyrotating the feed-cam is a one- Wey elut Automa ically con r lled meansar pr id d for e de in he one-wa c utch ineifective during certainperiods in the button.- holt s cy le s ha th stee-bv-step mo em nt f:the rk-c amp e ati e o th latera y vi aliv needle n be su pended o ashort ime in order that a suitable number of barring tit h s. m y be mae a t e e ds of e b nhe e The riod of he su pensi n f the ne way clu chis d rm n by the mar ban-stitch counting mechanism later to be dec ed-The automatically controlled means for rendering the one-way clutchineffective cornprises a spline 28 preferably extending the en.- tirelength of the feed-shaft 21 and operatively connected at its lower endto the clutch so that the raising of the spline will shift the clutchingelements of the clutch into an ineffective position. The spline isshifted up and down relative to the feed-shaft 2'! by means of a collar29 (Figs. 6 and 8) slidably mounted on the feed-shaft and securedpreferably by screws 30 to the spline 28. Formed in the collar 29 is anannular recess 3| enteredby a roller 32 carried on the inner end of alifting lever 33 freely pivoted on a fulcrumestud 34 journaled in spacedbearing lugs 35 (Fig. l) integral with the Wall of the bracket-arm I2.The lifting lever 33 is adapted to be actuated in a clockwise direction(Fig. 8) to raise the spline 28 and thereby render the One-Way clutchineffective, by a vertically disposed rocker 3.6 fixed on thefulcrum-stud 34. The lower end of the vertically disposed rocker is inperipheral contact with a eedam lea c uat n ment i the orm of a two-lobecam 31 (Fig. 10) which is fast upon the feed-shaft 21. Each lobe of thecam 3'! is cut with a gradual rise 38 terminating in a drop-off 39 sothat, as the feed-shaft 2'! is turned, the lower end of the rocker 36 isgradually swung outwardly in opposition to a coil spring 40 (Figs. 1 and6), which is anchored at one end to an arm M on the bracket-arm l2 andconnected at its other end to the lower end of a lever-arm 42 pinned tothe fulcrum-stud 34, As the outwardly swinging motion of the rocker .36is continued, a pawl-lever 43 (Figs. 1, 5, 6 and 8) pivotally carried onthe rocker 36 is raised relative to the lifting lever 33 until a step orshoulder 44 formed on the pawl-lever 43 moves above the level of theupper edge of the lifting lever 33 when, under the action of thespring-wire 45, the pawl-lever 43 snaps into a substantially verticalposition, i. e. from the position shown in Fig. 3 to that shown in Fig.5, thereby connecting the lifting lever 33 with the rocker 36. As thefeed-shaft v2'1 continues to turn and. th d op-e of e m 3 pa s s by thelower end of the rocker 36, the rocker snaps inwardly under theinfluence of the coil spring 40 and into a position determined by anadjustable stop 46 carried by the rocker 36. This rapid inward motion ofthe rocker 36, through the pawl-lever 43 and the lifting lever 33,raises the spline 28 and this forces the clutchelements of the one-wayclutch into ineffective position, As explained in my above mentionedPatent No. 2,411,493, when the clutch-elements are in their ineffectiveposition, the feed-shaft is not intermittently rotated, but remainsstationary. Thus the work-clamp is not shifted relatively to thelaterally vibratory needle.

It will be understood that during the step-bystep movements of thework-clamp the needle 2! is vibrated transversely of the line ofmovement of the work-clamp, To provide for this, the needle-bar 22 isendwise journaled in the needle-bar-gate 23 supported for vibratorymovements on the pintl-es 24. Connected to the upper end of the needlebar-gate 2 3 is one end of an endwise extensible link 46 adjustablyconnected at its other end to a vibratory lever 47 fulcrumed on apivot-stud 48 threaded into the bracket-arm l2. The vibratory lever 41is connected by a link 49 to one end of an actuating rock-lever 50supported in the slotted upper portion of a fulcrumedisk 5| seated forfree turning movement in a socket 52 formed in one end of afulcrum-carrying slide 53 slidable in .A a guideway 54 formed in thebracket-arm I 2. 'A plate 55 retains the actuating rock-lever 50 and thefulcrum-disk 5! in proper assembled relation in the fulcrum-carryingslide 53. The other end of the actuating rock-lever 50 is connected by alink 56 to one end of an oscillatory actuator-lever 51 (Fig. 4)fulcrurned on a stud 58 threaded intothe bracket-arm I2. 59 connectingthe link 56 to the oscillatory actuator-lever 51 is extended at itslower end and has journaled thereon a roller 60 (Fig. 8), which tracks acam-groove 61 formed in an operating driving element or cam 62 fast uponthe countershaft IS; the speed of rotation of which is onehalf that ofthe arm-shaft l4 during the normal buttonholing cycle. The stud 50'(Figs. 7 and 8) is provided with a roller at its lower end, which rollertracks a guide-slot 5| formed in a angle-bracket 52 secured to the sideof the bracket-arm I2. It will be understood from the above descriptionthat rotation of the cam A stud lobe.

where one of its drop-offs 39 passes by the 62 will cause theactuator-lever 51 to oscillate of the end of the link 46 on thevibratory-lever 41 permits regulation of the amplitude of vibration ofthe needle bar-gate 23 and hence the length of the stitches forming thebuttonhole.

To effect the production of the barrin stitches during the time that thestep-by-step movements of the work-clamp are suspended, the amplitude ofthe lateral vibrations of the needle is customarily increased preferablyto substantially twice that of the lateral vibrations of the needleduring the formation of the side stitches. The improvedmeans by whichthe amplitude ofthe vibration of the needle can be increased operates toeffect a shift of the fulcrum-disk 5! lengthwise of the guideway 54; theresult being to shift the fulcrum-axis of the actuating rock-lever 5!!and thereby change the effective lengths of the respective lever-arm ofthe rocklever 50. To this end, the rocker 36 is provided with anextension 63 (Figs. 3, 5, 7 and 9) having pivoted to its free end alatch 64 formed with a vertical shoulder 65 (Figs. 13 and 14); the latchfit being biased downwardly by a coilspring 66 into cooperative relationwith one end of a slide-shifting lever 6'! fulcrumed intermediate itsends on a pivot-stud 68. The other end of the slide-shifting lever 61 isforked to engage a roller 69 journaled on a pin ll! extending upwardlyfrom the fulcrum-carrying slide 53. As shown in Fig. 8, thefulcrum-carrying slide 53 is provided with a second roller 'H engaged bythe forked upper end of a lever 12 pivoted on the fulcrum-stud 34 andhaving connected to its lower end the coil-spring it. The coil-spring I3is provided to yieldingly maintain the fulcrum-carrying slide 53 in itsside-- stitching position, shown for example in Fig. 8. From the above,it will be understood that as the feed-shaft is intermittently rotatedto impart step-by-step movements to the work-clamp, the cam 3! likewiseturns and causes the rocker 36 to turn on its supporting fulcrum-stud 34(counterclockwise in Fig. 8). As the rocker 36 continues to turn, therocker-extension 63 moves inwardly, carrying with it the latch M, whichlatch slides across one end of the slide-shifting lever 5'! (Fig. 3)until its shoulder 65 moves beyond the edge of the lever 6'3. The spring66 then pulls the latch 54 downwardly so that the slide-shifting lever6'l becomes latched to the rocker 35, as shown in Fig. 5. The latchingtogether of the lever El and the rocker 36 occurs just before the cam3'! travels to the point where the lower end of the rocker 35 is inengagement with the high point of the cam- When the cam 31 rotates tothe point lower end of the rocker 35, the latter snaps inwardly underthe influence of the coil-spring 4!) into a position determined by theadjustable stop 45. During this rapid movement of the rocker 36 thefulcrum-carrying slide is quickly shifted from its side-stitchingposition (Fig. 3) to its bar-stitching position (Fig. 7). As previouslyexplained, the rapid drop-off of the rocker 36 from the high point onthe cam 31 also er fects a shift of the clutch-releasing spline 28; intoa position such that the feed-clutch is rendered ineffective and thestep-by-step movements of the work-clamp are terminated. It

will be appreciated that the termination of the feeding movements of thework-clamp and the increase in the amplitude of needle-vibration iseffected simultaneously, without any hesitation or interruption on thepart of either mechanism. This is desirable for the reason that thebarring stitches are formed in a neatly stacked arrangement at the endof the buttonhole and are not dispersed in any form of a spread pat--tern. It will be understood that the shifting from side-stitchingposition to bar-stitching position can be accomplished with facility inany position of the parts for the reason that the actuating rock-lever5G is continuously in engagement with its fulcrum-disk 5| and that,

in changing from side-stitching position to barstitching position, thefulcrum disk 5| is merely shifted longitudinally of the guideway 54 bythe rapid movement of the rocker 36.

The number of stitches included in each bar is determined by a suitablebar-stitch counting mechanism substantially the same in design as thatdisclosed in my previously mentioned Patent No. 2,411A93. The presentbar-stitch counting mechanism comprises a ratchet-wheel 14 mounted forlimited turning movement on the upper end of the fulcrum-stud 58 (Figs.4 and 9). Interposed between the head of a screw 15 threaded into theend of the fulcrum-stud 58 and the top of the fulcrum-stud 58 is a disk16 resting upon a coil-spring 'l'l having one of its ends anchored in ahole 18 formed in the stop 79 depending from a cover-plate 8i) andadapted to be clamped in desired set position by a thumb-nut 8i. Thatportion of the ratchet-wheel it which is normally biased into contactwith the adjustable stop '19 comprises an arcuate plate-member 82 (Fig.9) clamped for circular adjustment by screws 83 in an annular recess 84formed in the upper face of the ratchet-wheel 'M.

The ratchet-wheel i4 is adapted to be advanced in acounterclockwisedirection, as viewed in Figs. 4 and 9 by an actuating pawl 85 pivotallymounted on an extension 86 of the oscillatory actuatorlever 51; theactuating pawl 85- being biased into engagement with the teeth on theratchet-wheel M by a leaf-spring bl. Cooperating with the actuating pawl85 in advancing the ratchet-wheel M is a detent-pawl 88 which functionsto preclude retrograde turning of the ratchet-wheel. It will beunderstood that as the actuator-lever 5"; is oscillated about itsfulcrum-stud 58 by the cam 62, the actuating pawl 35 is operated insuch; a manner as to engage and advance the ratchet- I wheeltooth-by-tooth and that the detent-pawl 88 maintains the ratchet-wheelin its various steps of advancement. After the number of barringstitches to which the adjustable stop lQ'is set has been produced,during which time the ratchetwheel M is being advanced by theactuator-pawl 85, a trip-plate 89 adjustably secured in the recess 84formed in the ratchet-wheel M is brought into engagement with a pin 99depending from a crosslever 9| which is pivoted intermediate its ends ona stud 92 threaded into the cover-plate 80.

the action of the actuating pawl 85, swings the cross-lever 9i about itspivot 92 in the direction indicated by the arrow in Fig, 5, thus movingits free end into contact with the upstanding tail portion of thepawl-lever 43. Continued swinging movement of the cross-lever 9| turnsthe pawl-lever 43, against the action of the spring 45, thereby movingits shoulder id from its position vertically above the lifting lever 33to the position indicated in dotted lines in Fig. 12. Depending from thecross-lever 91 is a release-pin 93 to which is pivoted, adjacent thecross-lever 9|, a tripfinger 94 slidable between two guide pins 95 andformed at its free end with a wedge or inclined face 98 disposed toslide beneath the latch 64. After the cross-lever 9! has moved thepawl-lever 43 out of operative relation with the lifting lever 33,continued movement of the cross-lever will move the trip-finger 94 in adirection to cause its wedge-shaped end to slide beneath the latch 64and raise it about its pivot to release the slide" shifting lever El,permitting the coil-spring 3 to rapidly return the fulcrum-carryingslide 53 to its side-stitching position. During the release of the latch64, the lower end of the release pin 93 is adapted to move into contactwith the limb SI of a pawl 98 (Fig. 9) journaled on a ball-stud 99threaded into the upper end of the rocker 36. Further turning of thecross-lever ill, in response to the step-by-step advance of theratchet-wheel l4, swings the pawl 98 about the ball-stud 99 causing thelimb I of the pawl 98 to release a projection lBl on a reclutching leverHi2 pivoted at I03 on the bracket-arm l2. When the projection liii isreleased, the reclutching lever I02, under the influence of acoil-spring Illa, snaps from bar-stitching position (Fig. 9) toside-stitching position (Fig. 3) In moving from bar-stitching positionto side-stitching position, a cam-projection its on the reclutchinglever H32 engages a tail-member H36 on the ratchet-wheel actuating pawl85 and shifts the actuating pawl, in opposition to the leaf-spring 81,from its effective position shown in Fig. 9 to its inefiective positionshown in Figs. 3 and 5. As shown in Fig. 5, this shifting of theactuating pawl 85 causes it to move into engagement with the detent-pawl88 and shift the latter against its spring I01 out of engagement withthe teeth on the ratchet-wheel Hi. When the ratchet-wheel is thusreleased from the detent-pawl, the spring I! biases the ratchetwheel ina clockwise direction (Fig. 9) and against the stop 19., whereby thebar-stitch counting mechanism is reset for the subsequent barringoperation.

In order to resume the side-stitching operation at the completion of thebar-stitching operation, it is required that the clutch-releasing spline28 be lowered to permit the clutch-members to assume their wedgingrelation between the clutchdrum and the live clutch spider, in themanner disclosed in my previously mentioned Patent No. 2,411,493. In thepresent case, the reclutching lever W2 is fitted with a dependingadjustable abutment-screw Hi8, and this screw is adapted to strike theupper end of a spline-depressing bellcrank lever I09 (Fig. 6) when thereclutching lever is released from the pawl 95 at the completion of thebarring operation. As the bell-crank lever E09 turns under the blow ofthe abutmentscrew 108, the horizontal limb of the bell-crank lever (Fig.6) moves downwardly and a roller I I0 carried at the free end of thehorizontal limb of the lever I09 and disposed in the annular recess 3|of the collar 29 slides the collar downwardly on the feed-shaft 21. Thecollar, through the spline 8 I 28, renders the clutch again effective toturn the feed-cam.

From the above description, it will be understood that I have inventedan improved barring mechanism in which a change in the amplitude ofvibration of the sewing machine needle is efiected by merely shiftingthe fulcrum axis about which one of the members or the mechanism isoscillated. The fulcrum for said member is carried on a slide which isautomatically moved in one direction and spring returned after therequisite number of barring stitches is made. It .will be appreciatedthat by supporting the rock-lever 50 in a fulcrum disk 5! such that therock-lever is never separated from the fulcrum disk, the mechanism tochange the amplitude of vibration of the needle can be operated anytimein the buttonholing cycle. Its action in changing the amplitude ofneedle vibration is instantaneous, it can be performed without aclashing of the parts and with the expenditure of a minimum of effort.

Having thus set forth the nature of the invention, what I claim hereinis:

l. A buttonhole sewing machine having stitchforming mechanism includinga reciprocatory and laterally vibratory needle and barring mechanism forchanging the amplitude of vibration of the needle to sew barringstitches at an end of the buttonhole, said barring mechanism comprising,an operating driving element, an actuating rocklever operativelyconnected to said driving element and to said needle, a shiftablefulcrumsupport for said actuating rock-lever having a side-stitchingposition and a bar-stitching -position, a fulcrum-carrying slide towhich said fulcrum-support is attached, a spring for biasing saidfulcrum-carrying slide into one of its positions, releasable connectionsfor moving said slide and thereby said fulcrum-support to the other ofits positions against the action of said spring, and trip means for.separating said releasable connections and permitting said spring toreturn said slide to its other position.

2. A buttonhole sewing machine having stitchiorming mechanism includingareciprocatory and laterally vibratory needle and barring mechanism forchanging the amplitude of vibration of the needle to sew barringstitches at an end of the buttonhole, said barring mechanism.comprising, an operating driving element, an actuating rockleveroperatively connected to said driving element and to said needle, ashiftable fulcrumsupport for said actuating rock-lever having aside-stitching position and a bar-stitching position, a fulcrum-carryingslide to which said fulcrum-support is attached, a spring for biasingsaid fulcrum-carrying slide in a direction to move said fulcrum-supportinto its side-stitching position, cam-controlled releasable connectionsfor moving said slide and thereby said fulcrum support to bar-stitchingposition against the action of said spring, a bar-stitch counting devicefor controlling the number of stitches in the bar, and trip meansassociated with said bar-stitch counting device for separating saidreleasable connections and permitting said spring to return saidfulcrum-support to its side-stitching position.

3. A buttonhole sewing machine having stitchforming mechanism includinga reciprocatory and laterally vibratory needle and barring mechanism forchanging the amplitude of vibration of the needle to sew barringstitches at an end of the buttonhole, said barring mechanism comprising,an operating driving element, an actuating rocklever operativelyconnected to said driving element and to said needle, :3, support forsaid actuating rock-lever including a fulcrum-disk slotted for slidinglyengaging said actuating rock-lever,

a supporting slide on which said fulcrum-disk is to said needle, afulcrum-carrying slide supported 5 for end'wise movement and having asocket formed therein, a fulcrum-disk rotatably seated in said socketand formed with a slot to slidingly engage said actuating rock-lever, aspring for biasing said fulcrum-carrying slide in one direction, andoperative connections for shifting said fulcrumcarrying slide in theopposite direction.

ALFRED R. WOOD.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 694,150 Hogan Feb. 25, 19021,459,374 Leveque June 19, 1923

